This release includes 1 breaking change for platform teams planning a safe upgrade.
✓ No known CVEs patched in this version
Topics
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Summary
AI summaryDropped the temperature field for all gpt-5.x reasoning models, which reject non-default values.
Full changelog
Fix
Drop temperature field for gpt-5.x reasoning models.
The useNewTokenParam branch already correctly used max_completion_tokens for these models, but it still passed temperature: 0.7 which all gpt-5.x reasoning models reject with:
400 Unsupported value: 'temperature' does not support 0.7 with this model. Only the default (1) value is supported.
This affected gpt-5, gpt-5.1, gpt-5.2, gpt-5.3, gpt-5.4, gpt-5.5 (released 2026-04-23), and the o-series.
What still works
The older gpt-4.x branch (useNewTokenParam=false) keeps temperature: 0.7 since gpt-4.x models still accept it.
Verified
- Direct probe of
gpt-5.5-2026-04-23: HTTP 200, valid completion, no temperature in request body - Hit while running a 3-round brainstorm with
openai:gpt-5.5 + deepseek:deepseek-chat— gpt-5.5 voice errored every round-1 turn until this fix.
Breaking Changes
- Removed `temperature` field for all gpt-5.x reasoning models (e.g., gpt-5, gpt-5.1‑5.5, o-series).
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About spranab/brainstorm-mcp
Multi-round AI brainstorming debates between multiple models (GPT, Gemini, DeepSeek, Groq, Ollama, etc.). Pit different LLMs against each other to explore ideas from diverse perspectives.
Related context
Beta — feedback welcome: [email protected]